1. Field of the Invention
The present invention relates to a power steering apparatus and a method of assembling the power steering apparatus.
2. Description of Related Art
In a motor-driven power steering apparatus (EPS) that is an example of a steering apparatus for a vehicle, the examples of an EPS having a rack and pinion steering gear include a pinion assistance EPS that drives a pinion meshing with a rack shaft, a rack assistance EPS that drives the rack shaft itself, and the like.
Here, typically, in the pinion assistance EPS, an electric motor drives the pinion based on a steering torque. The pinion assistance EPS has a problem in that a steering gear box increases in size due to the installation of the electric motor, thereby limiting the mounting of the EPS in a vehicle, or the arrangement of the EPS in an engine room.
A dual pinion EPS is proposed in which a pinion driven by an electric assisting mechanism is provided separately from a pinion connected to a steering shaft, and the electric motor can be disposed at a desired position on the rack shaft (refer to JP-UM-B-02-021346 as an example).